GEMS project

5E Lesson Plan #2

AUTHORS’ NAMES: Nikki Ulaszek Benjamin & Sarah Martinez
TITLE OF THE LESSON: Swirling Colors
TECHNOLOGY LESSON: No
DATE OF LESSON: October 5, 2007
LENGTH OF LESSON: 30-50 minutes
NAME OF COURSE: 2^nd Grade Science
SOURCE OF THE LESSON: LHS GEMS Teacher’s Guide: Liquid Explorations Activity 2: Swirling Colors
TEKS ADDRESSED:

2.2 Scientific processes. The student develops abilities necessary to do scientific inquiry in the field and the classroom. The student is expected to:

(B) plan and conduct simple descriptive investigations

(E) construct reasonable explanations and draw conclusions using information and prior knowledge

(F) communicate explanations about investigation

2.3 Scientific processes. The student knows that information and critical thinking are used in making decisions. The student is expected to:

(A) make decisions using information

(B) discuss and justify the merits of decisions

2.7 Science concepts. The student knows that many types of change occur. The student is expected to:

(A) observe, measure, record, analyze, predict, and illustrate changes in size, mass,

temperature, color, position, quantity, sound, and movement

CONCEPT STATEMENT: There is a difference between a “mixture” and a solution. A “mixture” is a combination of two materials that do not react. A solution is a special kind of mixture in which mixing occurs at the molecular level. Hence, a solution is a mixture, but a mixture os not always a solution.
http://www.princeton.edu/~pmi/outreach/scsp/mixturesandsolutions/background.htm

PERFORMANCE OBJECTIVES:
Given different solutions, students will be able to:

1. Describe the swirl pattern seen after food coloring is added.
2. Compare the swirl patterns of the added food coloring.
3. Explain why salt water and plain water are different.

RESOURCES:
FOR THE CLASS

· 1 pitcher, 2-4 quart capacity (2-4 liters)

· 1 clear wide-mouthed container, 2-4 quart capacity (2-4 liters). A large jar or the bottom cut from a 2-liter clear, plastic colorless soda bottle will work.

· 3 quart or liter bottles of salt-free seltzer water

· 2 lemons

· 1 knife (for cutting lemons)

· ¾ cup sugar

· Container to hold sugar

· 1 tablespoon

· 1 plastic stir stick (coffee stirrers or popsicle sticks work well)

· 1 long-handled spoon

· 1 squeeze bottle of red food coloring

· 1 squeeze bottle of blue food coloring

· 1 blank piece of paper

· 1 bucket, or access to a sink

· Paper towels or sponges

· A chalkboard or a large piece of paper

FOR EACH PAIR OF STUDENTS

· 3 tall, clear plastic cups, 10-ounces (the taller the cup, the better the opportunity to see the downward spiral pattern of the swirls)

· 2 small paper cups

· 2 container of salt, such as a margarine tub or other wide-mouthed container

· 5 teaspoons kosher or pickling salt (kosher or pickling salt are preferable because when dissolved, they leave no visible trace. The additives in most other varieties of table salt cause water to look cloudy. If additive-free salt is unavailable, any table salt will work.)

· 1 plastic stir stick

· 1 teaspoon-sized spoon

· 2 crayons

· 2 pencils

· 2 “Swirling Colors” data sheets

SAFETY CONSIDERATIONS: Students will be working with liquids and food coloring, so there should be a mop and/or paper towels nearby in case of spills. There should also be clean water available for students to wash hands if necessary. If a spill occurs, the students should inform the teacher immediately.
Prior to the activity, a letter may be sent home with students informing parents of the potential need for students to wear clothing on the day of the activity that food coloring may stain.

SUPLEMENTARY MATERIALS, HANDOUTS: “Swirling Colors” data sheet

Engagement		Time: 10 mins
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Today we’re will continue to explore liquids. This time, you will observe the ways drops of food coloring move through different liquids.
	1. What did we learn about liquids in the activity yesterday?	1. They flow, and they take the shape of the container.
Make sugar water solution while explaining to students what you are doing. Stir solution.
Tell me when you cannot see the sugar anymore. Even though the water looks the same, it has changed; it is now sugar water.	1. What is in the container?	1. Water. Sugar water. Sugar and water. Ohhh …… Ahhhh ……
After water is no longer moving, …	… 1. What do you think would happen if Iadd one drop of red food coloring to the surface of the liquid	1. It will turn red. [It will turn pink.] [It will not do anything.] [It will make a trail of red.]
Add 1 drop of red food coloring. Instruct students to observe what happens and emphasize importance of not jiggling, stirring, or blowing on the liquid.
Hold up sketch made before class on poster board of water container. Place crayon where you added food coloring.	1. Can anyone describe what you saw after the food coloring was added?	1. Observations shared by 1 student. As student answers, draw what is being described.
This drawing shows the way food coloring moves through sugar water. You will watch and record how food coloring moves through plain water, salt water, and bubbly water.
	Will the trails look different or the same in the three different liquids?	1. [They will look different.] They will look the same.

Exploration		Time: 15 - 20 mins
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Now it is your turn! You will be working in pairs. One student will keep the cups in front of you on the paper and the other will measure and stir. BOTH of you will record what happens to the drop with a crayon and data sheet!
INITIAL INSTRUCTIONS: The first liquid you will investigate is plain water. Do NOT add any salt to it. Write on board ... "Plain - Salt." The second liquid will be salt water. Before the drop of food coloring is added, you must add salt to the water. *AFTER* you have made the salt water, raise your hand and I will come over to add the drop of food coloring to the plain water cup. You will draw what you observe when the drop is placed in the cup. BEGIN DRAWING AS SOON AS THE FOOD COLORING IS ADDED TO THE CUPS!
“Measurers,” please add 4 teaspoons of salt to the middle cup and then stir until you cannot see the salt anymore. We cannot add the drop of food coloring to your salt water until the liquid is completely still so try not to move it.
The first cup is plain water. You should being drawing what you see RIGHT AFTER I add the food coloring. Circulate around room, placing a drop of BLUE food coloring in each cup of plain water. Allow time for students to draw. After about one minute, ask students to put down their crayons.
Have 1-2 students collect the salt containers, sir sticks, and spoons, as you distribute the food coloring, so there aren’t any “side experiments.”
	1. What did you see? 2. Did anyone else see the same thing?	1. Observations shared by volunteer. 2. Yes … No …
Please raise your hand if your salt water is still. You should being drawing what you see RIGHT AFTER I add the food coloring. Circulate around room, placing a drop of food coloring in each cup of salt water. Remember to begin drawing RIGHT AWAY.
	1. What did you see? 2. Did anyone else see the same thing?	1. Observations shared by volunteer. 2. Yes … No …
While students are drawing, open seltzer water bottles. When students are ready, fill each team’s third cup half full. Circulate around room adding drop of food coloring to bubbly water. Remember to begin drawing IMMEDIATELY.	1. How does this compare with plain water?	1. Observations shared.
	1. What did you see? 2. Did anyone else see the same thing?	1. Observations shared by volunteer. 2. Yes … No …

Explanation		Time: 5-10 mins
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Take bucket around to each pair and have them empty their cups into it. Please come to the discussion area with your drawings.
On chalkboard, draw 3 cups and labels … Plain Water, Salt Water, and Bubbly Water.
	I need 2 volunteers to hold up their data sheets for each liquid and describe what you saw. As they describe their observations, draw what they are saying on the board.
Help the class summarize how the different liquids changed the way the food coloring moved.	Who can help me summarize the way the food coloring moved through the different liquids?	Plain water – Slowly swirl and move through the liquid Salt Water – Food coloring starts to sink and then returns to upper part of cup Bubbly Water – Food coloring disperses quickly
Even though the liquids look similar, what happened to the food coloring shows us that they are different.	Why? What is happening?

Elaboration		Time: 3 mins
What the Teacher Will Do	Probing Questions	Student Responses Potential Misconceptions
Demo Into vial, add salt (at bottom) and rice (at top). Mark the level of the rice with a permanent marker. Allow students to see this up close to confirm. Invert the vial. [The salt will fill the spaces and take up less volume. Salt fills in spaces in water so food coloring cannot get through (density).]	1. What happened and why? 2. What are the bubbles doing? [Similar to when stir KoolAid ... or lemonaid as we will do in a few minutes.]	1. The salt filled in the spaces between the rice. 2. Students share thoughts
Squeeze lemons into the sugar water left from the demonstration. Pour this pink lemonade into paper cups for the students. Drink and enjoy!	Who can tell me what we have made?	Pink lemonade Lemonade Kool-Aid

Evaluation

Time: 1-2 mins

What the Teacher Will Do

Probing Questions

Student Responses

Potential Misconceptions

Students will turn in their “Swirling Colors” handout.